A compact waveguide crossing structure with low transmission losses and negligible crosstalk is demonstrated for silicon-on-insulator circuits. The based on a mode expander optimized by means of genetic algorithm leading to lower than 0.2 dB reflection below 40 in broad bandwidth 20 nm. Furthermore, the resulting has footprint only 6x6 microm(2) does not require any additional fabrication steps.

A novel approach to reduce the coupling length and increase coefficient in waveguide directional couplers implemented on two-dimensional (2-D) photonic crystals (PhC) is proposed. To of a 2-D PhC coupler, which composed two parallel waveguides separated by one or several rows rods, radius rods between both reduced. The application this feature ultrasmall channel interleavers wavelength demultiplexers addressed.

Electrically thin and effectively 2-D material composites, metasurfaces, have been widely exploited for the manipulation of electromagnetic waves. For many applications, it is desired to transform incident waves a specific frequency range keeping metasurface invisible at other frequencies. Such frequency-selective response can be achieved based on subwavelength Huygens' inclusions. However, their fabrication requires sophisticated processes due 3-D geometry. Here, we propose planar meta-atom...

Reconfigurable intelligent surfaces (RISs) are a promising tool for the optimization of propagation channels advanced wireless communication systems. These tools especially relevant high-frequency (millimeter-band) links where directive antennas used. RIS panels act as high-gain passive repeaters, whose reflected waves interfere with from illuminated spots at supporting walls, creating complex field pattern in far zone. In this work, we consider particular scenario RISs anomalous reflection...

Active development is taking place in reconfigurable and static metasurfaces that control optimize reflections. However, existing designs typically only reflections from the metasurface panels, neglecting interference with originating supporting walls nearby objects. In this study, we investigate how engineering properties can modify total scattering pattern, enabling modification optimization of significantly larger illuminated areas than panel. To accomplish this, a general design approach...

In conventional inductive wireless power devices, the energy is transferred via only reactive near fields, which equivalent to nonradiative F\"orster transfer in optics. Radiation from transmitting and receiving coils usually considered as a parasitic effect that reduces power-transfer efficiency. As long distance between two antennas small compared antenna size, devices offer rather high efficiency, of order 80%--90%. However, for larger distances, efficiency dramatically drops, making such...

Most applications of metasurfaces require excitation and control both electric magnetic surface currents. For such purpose, the metasurface must have a finite thickness to handle sheets negligible that offer only response, coherent illumination can compensate need create discontinuities tangential field component using known are space-uniform plane-wave absorption specular reflection. However, it is also periodical space-modulated (inhomogeneous) be used realize anomalous reflection,...

The performance of a directional coupler based on photonic crystal waveguides is theoretically studied and experimentally verified at microwave frequencies. Simulation results using time domain method confirm the theoretical analysis show good agreement with measurements. It shown that coupling lengths as short 3.5λ can be attained from this approach. Photonic couplers are envisaged key building-block in ultra-compact integrated circuits such optical modulators, wavelength demultiplexers or...

We propose and analyse metasurface-bound invisible (non-scattering) partially open cavities where the inside field distribution can be engineered. It is demonstrated both theoretically experimentally that exhibit unidirectional invisibility at operating frequency with enhanced or suppressed different positions cavity volume. Several examples of applications designed are proposed analyzed, in particular, cloaking sensors obstacles, enhancement emission, "invisible waveguides". The...

The increasing complexity of embedded applications combined with the advances in chip integration make design process a very challenging task. Due to this rising complexity, under performance, area and consumption constraints system-on-a-chip (SOC) composed mixed software-hardware units, becomes increasingly intricate. This paper presents method an associated tool (CODEF) which allow designer do automatic and/or interactive system space exploration order construct cost effective real-time...

Inhomogeneous metasurfaces have shown possibilities for unprecedented control of wave propagation and scattering. While it is conventional to shine a single incident plane from one side these metastructures, illuminating by several waves simultaneously both sides may enhance scattered waves, which results in additional functionalities novel applications. Here, we unveil how using coherent plane-wave illumination properly designed inhomogeneous metasurface sheet possible realize controllable...

A detailed analysis of adiabatic coupling between conventional photonic crystal single-line-defect and coupled-resonator optical waveguides is reported. Adiabatic by progressive variation the radii spacing defects cavities investigated. Flat transmission spectra with efficiencies greater than 90% are achieved in a broad frequency range short lengths. Moreover, we find that flat at low frequencies requires longer lengths partly because requirements imposed for crystals violated.

We propose a structure that allows the splitting of electromagnetic waves with phase shift 180° between output signals based on photonic crystals. The consists two parallel coupled-cavity waveguides placed in proximity. performance is theoretically discussed, evaluated by means finite-difference time-domain method simulations and experimentally demonstrated at microwave frequencies. As both paths have same physical length, are synchronized, which very attractive for high-speed optical...

Resonators composed of two mirrors, such as Fabry-Perot cavities, provide a simple but effective approach to achieve wave transmission with high finesse. Further increase the quality factor requires reflectors higher conductivity or multi-mirror solutions. However, analytical complexity resonators more than mirrors prevents design optimal structures without recurring numerical methods. This work considers an alternative this problem by using cavities which do not produce any electromagnetic...

This study explores the potential enhancement of radio signal propagation in intricate environments through deployment basic resonant dipole scatterers. We employ MATLAB ray tracer algorithm to examine impact dipolar scatterers on power received at user’s location. The tracing model is modified for a scatterer based its bi-static scattering cross-section. Our analytical and simulation results indicate that extra components nearly ineffective when direct link present. Conversely, scenarios...

In the paper above, there is a mistake in one of expressions that represents equivalent path-loss between transmitter, metasurface designed as perfect anomalous reflector, and receiver.More accurately, representation gain parameter includes term should not be present.

Metasurfaces are efficient and versatile electromagnetic structures that have already enabled the implementation of a wide range microwave photonic wave shaping applications. Despite extensive research into metasurfaces, rigorous comprehensive understanding their angular dispersion remains vastly under-explored. Here, we use generalized sheet transition conditions (GSTCs) to model analyze dispersive properties metasurfaces. Based on this theoretical framework, demonstrate metasurface may...

This study explores the potential enhancement of radio signal propagation in intricate environments through deployment basic resonant dipole scatterers. We employ MATLAB ray tracer algorithm to examine impact dipolar scatterers on power received at user's location. The tracing model is modified for a scatterer based its bi-static scattering cross-section. Our analytical and simulation results indicate that extra components nearly ineffective when direct link present. Conversely, scenarios...

High-frequency (millimeter-wave) wireless communications require the use of directive, high-gain antennas, as otherwise achievable length communication link quickly decreases with increasing frequency. In order to provide necessary space coverage, anomalously reflecting and reconfigurable intelligent surfaces can be possibly used. this presentation, we will discuss our recent results on analytical estimations budget in presence such reflectors. Using concept macroscopic reflection...

One of the biggest challenges Astrobiology is search for clear signs present or past life on other planetary bodies. Thus, this poster will describe project "Photonic Biosensor Space Application" (PBSA, www.pbsa-fp7.eu) founded by Directorate-General Enterprise and Industry (DG ENTR) within European Commission managed Unit S2 (Space Research) Research Agency (REA).

Un componente crítico de un vehículo aéreo no tripulado (VANT) es el sistema comunicaciones. Éste se encarga transmitir la información aeronave hacia estación base y enviar configuraciones aeronave. Es importante mantener enlace comunicaciones, considerando que los recursos energéticos limitan autonomía operación Por este motivo artículo plantea antena inteligente baja complejidad administre potencia transmisión del comunicaciones en función posición utilizando módulo posicionamiento parte...